Straight trucks generally include a single frame, or chassis, on which all axles, the tractor cab, and the truck body are mounted. For example, a floor assembly of the truck body is mounted onto main rails of the chassis, which extend the length of the chassis. Conventional steel truck bodies include a floor assembly with steel beams extending a length of the truck body, steel cross-members above the steel rails, and a floor that rests on the steel cross-members. To mount the truck body onto the chassis, each steel beam is positioned over a main rail of the chassis, a mounting plate is placed above the steel rail and below the main rail, and the mounting plates are connected (e.g., by rods and fasteners) to sandwich together the steel beam and the main rail.
Composite truck bodies, on the other hand, include a one-piece floor assembly molded to include integral main beams. Because of this integral molded design, mounting plates cannot be placed above the main beams to couple the truck body to main rails of a chassis. As a result, mounting brackets are coupled to the main beams (e.g., via an adhesive), and the mounting brackets are then connected to mounting plates positioned below the main rails.
Composite truck bodies may provide advantages over steel truck bodies, such as lighter weight (equating to more load capacity), better insulation, more shock absorption, and corrosion resistance. However, composite truck bodies may suffer from a weaker coupling between the composite floor assembly and a chassis, as compared to steel truck bodies. In particular, heavy loads, large translational forces (such as the truck body striking a bridge), or general wear and tear may cause the adhesive bond between the mounting bracket and the main beam to fail, uncoupling the truck body from the chassis.